[infer][java] do not report `return not nullable` on lambdas

Summary: It is not clear how to add annotations on lambdas.

Reviewed By: sblackshear

Differential Revision: D4741851

fbshipit-source-id: bf40867

infer/src/IR/Typ.re

@@ -605,6 +605,10 @@ let module Procname = {
     fun
     | Java j => equal_method_kind j.kind Static
     | _ => false;
+  let java_is_lambda =
+    fun
+    | Java j => String.is_prefix prefix::"lambda$" j.method_name
+    | _ => false;
 
   /** Prints a string of a java procname with the given level of verbosity */
   let java_to_string withclass::withclass=false (j: java) verbosity =>

infer/src/IR/Typ.rei

@@ -378,6 +378,9 @@ let module Procname: {
       Note: currently only checks that the last argument has type Object[]. */
   let java_is_vararg: t => bool;
 
+  /** Check if the proc name comes from a lambda expression */
+  let java_is_lambda: t => bool;
+
   /** Check if the last parameter is a hidden inner class, and remove it if present.
       This is used in private constructors, where a proxy constructor is generated
       with an extra parameter and calls the normal constructor. */

infer/src/eradicate/eradicateChecks.ml

@@ -360,6 +360,8 @@ let check_return_annotation tenv
   let ret_annotated_nonnull =
     Annotations.ia_is_nonnull ret_ia in
   match ret_range with
+  (* Disables the warnings since it is not clear how to annotate the return value of lambdas *)
+  | Some _ when Typ.Procname.java_is_lambda curr_pname -> ()
   | Some (_, final_ta, _) ->
       let final_nullable = TypeAnnotation.get_value AnnotatedSignature.Nullable final_ta in
       let final_present = TypeAnnotation.get_value AnnotatedSignature.Present final_ta in

infer/tests/codetoanalyze/java/eradicate/ReturnNotNullable.java

@@ -15,6 +15,7 @@ import java.net.URL;
 import java.io.BufferedReader;
 import java.io.FileReader;
 import java.io.IOException;
+import java.util.stream.Stream;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
@@ -146,4 +147,9 @@ public class ReturnNotNullable {
         return x.f1; // can be null
     }
   }
+
+  Stream<Object> methodUsesLambda(Stream<Object> stream) {
+    return stream.map(x -> null); // Intentionaly not reporting here
+  }
+
 }

infer/tests/codetoanalyze/java/eradicate/issues.exp

@@ -55,14 +55,14 @@ codetoanalyze/java/eradicate/PresentTest.java, Optional PresentTest$TestPresentA
 codetoanalyze/java/eradicate/PresentTest.java, Optional PresentTest$TestPresentAnnotationBasic.returnPresentBad(), 1, ERADICATE_VALUE_NOT_PRESENT, [origin,The value of `PresentTest$TestPresentAnnotationBasic.absent` in the call to `get()` is not `@Present`. (Origin: field PresentTest$TestPresentAnnotationBasic.absent at line 47)]
 codetoanalyze/java/eradicate/PresentTest.java, void PresentTest$TestPresentAnnotationBasic.testOptionalAbsent(), 1, ERADICATE_PARAMETER_VALUE_ABSENT, [origin,`expectPresent(...)` needs a present value in parameter 1 but argument `absent()` can be absent. (Origin: call to absent() at line 65)]
 codetoanalyze/java/eradicate/PresentTest.java, void PresentTest.testPresent(Optional,Optional), 4, ERADICATE_PARAMETER_VALUE_ABSENT, [`argPresent(...)` needs a present value in parameter 1 but argument `absent` can be absent. (Origin: method parameter absent)]
-codetoanalyze/java/eradicate/ReturnNotNullable.java, Object ReturnNotNullable$ConditionalAssignment.test(boolean), 0, ERADICATE_RETURN_NOT_NULLABLE, [origin,Method `test(...)` may return null but it is not annotated with `@Nullable`. (Origin: field ReturnNotNullable$ConditionalAssignment.f1 at line 146)]
+codetoanalyze/java/eradicate/ReturnNotNullable.java, Object ReturnNotNullable$ConditionalAssignment.test(boolean), 0, ERADICATE_RETURN_NOT_NULLABLE, [origin,Method `test(...)` may return null but it is not annotated with `@Nullable`. (Origin: field ReturnNotNullable$ConditionalAssignment.f1 at line 147)]
-codetoanalyze/java/eradicate/ReturnNotNullable.java, Object ReturnNotNullable.tryWithResourcesReturnNullable(String), 0, ERADICATE_RETURN_NOT_NULLABLE, [origin,Method `tryWithResourcesReturnNullable(...)` may return null but it is not annotated with `@Nullable`. (Origin: call to returnNullOK() at line 91)]
+codetoanalyze/java/eradicate/ReturnNotNullable.java, Object ReturnNotNullable.tryWithResourcesReturnNullable(String), 0, ERADICATE_RETURN_NOT_NULLABLE, [origin,Method `tryWithResourcesReturnNullable(...)` may return null but it is not annotated with `@Nullable`. (Origin: call to returnNullOK() at line 92)]
 codetoanalyze/java/eradicate/ReturnNotNullable.java, String ReturnNotNullable.redundantEq(), 0, ERADICATE_RETURN_OVER_ANNOTATED, [Method `redundantEq()` is annotated with `@Nullable` but never returns null.]
 codetoanalyze/java/eradicate/ReturnNotNullable.java, String ReturnNotNullable.redundantEq(), 2, ERADICATE_CONDITION_REDUNDANT_NONNULL, [The condition s is always false according to the existing annotations.]
 codetoanalyze/java/eradicate/ReturnNotNullable.java, String ReturnNotNullable.redundantNeq(), 0, ERADICATE_RETURN_OVER_ANNOTATED, [Method `redundantNeq()` is annotated with `@Nullable` but never returns null.]
 codetoanalyze/java/eradicate/ReturnNotNullable.java, String ReturnNotNullable.redundantNeq(), 2, ERADICATE_CONDITION_REDUNDANT_NONNULL, [The condition s is always true according to the existing annotations.]
-codetoanalyze/java/eradicate/ReturnNotNullable.java, String ReturnNotNullable.returnNull(), 0, ERADICATE_RETURN_NOT_NULLABLE, [origin,Method `returnNull()` may return null but it is not annotated with `@Nullable`. (Origin: null constant at line 34)]
+codetoanalyze/java/eradicate/ReturnNotNullable.java, String ReturnNotNullable.returnNull(), 0, ERADICATE_RETURN_NOT_NULLABLE, [origin,Method `returnNull()` may return null but it is not annotated with `@Nullable`. (Origin: null constant at line 35)]
 codetoanalyze/java/eradicate/ReturnNotNullable.java, String ReturnNotNullable.returnNullable(String), 0, ERADICATE_RETURN_NOT_NULLABLE, [Method `returnNullable(...)` may return null but it is not annotated with `@Nullable`. (Origin: method parameter s)]
-codetoanalyze/java/eradicate/ReturnNotNullable.java, String ReturnNotNullable.return_null_in_catch(), 0, ERADICATE_RETURN_NOT_NULLABLE, [origin,Method `return_null_in_catch()` may return null but it is not annotated with `@Nullable`. (Origin: null constant at line 110)]
+codetoanalyze/java/eradicate/ReturnNotNullable.java, String ReturnNotNullable.return_null_in_catch(), 0, ERADICATE_RETURN_NOT_NULLABLE, [origin,Method `return_null_in_catch()` may return null but it is not annotated with `@Nullable`. (Origin: null constant at line 111)]
-codetoanalyze/java/eradicate/ReturnNotNullable.java, String ReturnNotNullable.return_null_in_catch_after_throw(), 0, ERADICATE_RETURN_NOT_NULLABLE, [origin,Method `return_null_in_catch_after_throw()` may return null but it is not annotated with `@Nullable`. (Origin: null constant at line 122)]
+codetoanalyze/java/eradicate/ReturnNotNullable.java, String ReturnNotNullable.return_null_in_catch_after_throw(), 0, ERADICATE_RETURN_NOT_NULLABLE, [origin,Method `return_null_in_catch_after_throw()` may return null but it is not annotated with `@Nullable`. (Origin: null constant at line 123)]
-codetoanalyze/java/eradicate/ReturnNotNullable.java, URL ReturnNotNullable.getResourceNullable(Class,String), 0, ERADICATE_RETURN_NOT_NULLABLE, [origin,Method `getResourceNullable(...)` may return null but it is not annotated with `@Nullable`. (Origin: call to getResource(...) modelled in eradicate/modelTables.ml at line 127)]
+codetoanalyze/java/eradicate/ReturnNotNullable.java, URL ReturnNotNullable.getResourceNullable(Class,String), 0, ERADICATE_RETURN_NOT_NULLABLE, [origin,Method `getResourceNullable(...)` may return null but it is not annotated with `@Nullable`. (Origin: call to getResource(...) modelled in eradicate/modelTables.ml at line 128)]